1. Field of the Invention
The present application relates generally to virtualization of ports. More particularly, the present application relates to a computer implemented method, data processing system, and computer usable program code for using N_Port ID virtualization to extend the virtualization capabilities of the FC-SB-3 protocol as well as other protocols.
2. Description of the Related Art
N_Port ID virtualization (NPIV) allows a single fibre channel node port (N_Port) to register multiple worldwide port names (WWPN) with a fabric name server. A worldwide port name is a unique name in a fibre channel storage area network. Each registered worldwide port name is assigned a unique identifier, such as a N_Port ID, when it connects to a fabric. With N_Port ID virtualization, a single fibre channel node port may appear as multiple worldwide port names in the fibre channel fabric. Usage of N_Port ID virtualization in today's environment is usually limited to protocols that do not provide the capability to address individual logical images within a host system. One such protocol is the fibre channel protocol for small computer system interface (FCP-SCSI). Without N_Port ID virtualization, the FCP-SCSI is incapable of identifying the sender of a command as one of a plurality of host system logical images unless each logical image uses a dedicated fibre channel protocol host adapter. Since the sender of a SCSI command always needs to be identified regardless of whether it is a logical image or a physical system, the inability of the FCP-SCSI to identify host logical images requires the use of a dedicated fibre channel protocol host adapter for each host logical image. After N_Port ID virtualization was developed, there was no longer a need to assign a dedicated fibre channel protocol host adapter to each host logical image, since N_Port ID virtualization provides the addressing capability that identifies the sender of a command as one of a plurality of host logical images.
A similar situation exists in protocols such as the fibre channel—single-byte command code sets mapping-3 (FC-SB-3) protocol, also known as FICON protocol, even where such protocols have the ability to identify individual host logical images. For example, if a host system contains multiple independent partitions and each partition requires the use of the host logical image addressing capability provided by the FICON protocol, then there is a need to use N_Port ID virtualization to extend the addressing capability of each logical partition. An example of such a system is one in which part of the system processing capability is rented to individual customers, each of which requires that its partition have all of the characteristics that it would have if it were using dedicated hardware. In these systems, a dedicated FICON adapter has been required in order to support each such partition because that was the only way to make all of the FICON logical paths available to the customer. This has resulted in excessive system cost when several such partitions exist.
Also, protocols such as FICON addressed the end-to-end connectivity within their unique upper level protocols. As a result, functions only dealt with at the lower levels, such as zoning and other management functions, can only deal with FICON protocol at the physical level. This causes the scope of all of these functions to be for all partitions sharing the adapter, rather than being able to deal with the individual partition. This is a problem even in environments which only involve a single enterprise.